Fold CFGAS_Stream into CFGAS_TextStream.

Every CFGAS_Stream is wrapped inside a CFGAS_TextStream. This CL folds
the two classes together and merges the methods where needed.

Change-Id: Ic56449b36baa51254d8d600ce631f285ba2cbb80
Reviewed-on: https://pdfium-review.googlesource.com/4057
Commit-Queue: dsinclair <dsinclair@chromium.org>
Reviewed-by: Nicolás Peña <npm@chromium.org>

2 files changed, 67 insertions, 221 deletions

diff --git a/xfa/fgas/crt/ifgas_stream.cpp b/xfa/fgas/crt/ifgas_stream.cpp
index fa9b8db02d..712243d701 100644
--- a/xfa/fgas/crt/ifgas_stream.cpp
+++ b/xfa/fgas/crt/ifgas_stream.cpp
@@ -40,11 +40,6 @@ class IFGAS_StreamImp {
 
  protected:
   IFGAS_StreamImp();
-
-  uint32_t GetAccessModes() const { return m_dwAccess; }
-
- private:
-  uint32_t m_dwAccess;
 };
 
 class CFGAS_FileReadStreamImp : public IFGAS_StreamImp {
@@ -81,8 +76,7 @@ class CFGAS_FileWriteStreamImp : public IFGAS_StreamImp {
   CFGAS_FileWriteStreamImp();
   ~CFGAS_FileWriteStreamImp() override {}
 
-  bool LoadFileWrite(const CFX_RetainPtr<IFX_SeekableWriteStream>& pFileWrite,
-                     uint32_t dwAccess);
+  bool LoadFileWrite(const CFX_RetainPtr<IFX_SeekableWriteStream>& pFileWrite);
 
   // IFGAS_StreamImp:
   int32_t GetLength() const override;
@@ -103,42 +97,12 @@ class CFGAS_FileWriteStreamImp : public IFGAS_StreamImp {
   int32_t m_iPosition;
 };
 
-class CFGAS_Stream : public IFGAS_Stream {
- public:
-  template <typename T, typename... Args>
-  friend CFX_RetainPtr<T> pdfium::MakeRetain(Args&&... args);
-
-  // IFGAS_Stream
-  uint32_t GetAccessModes() const override;
-  int32_t GetLength() const override;
-  int32_t Seek(FX_STREAMSEEK eSeek, int32_t iOffset) override;
-  int32_t GetPosition() override;
-  bool IsEOF() const override;
-  int32_t ReadData(uint8_t* pBuffer, int32_t iBufferSize) override;
-  int32_t ReadString(wchar_t* pStr, int32_t iMaxLength, bool& bEOS) override;
-  int32_t WriteData(const uint8_t* pBuffer, int32_t iBufferSize) override;
-  int32_t WriteString(const wchar_t* pStr, int32_t iLength) override;
-  void Flush() override;
-  bool SetLength(int32_t iLength) override;
-  int32_t GetBOM(uint8_t bom[4]) const override;
-  uint16_t GetCodePage() const override;
-  uint16_t SetCodePage(uint16_t wCodePage) override;
-
- private:
-  CFGAS_Stream(std::unique_ptr<IFGAS_StreamImp> imp, uint32_t dwAccess);
-  ~CFGAS_Stream() override;
-
-  std::unique_ptr<IFGAS_StreamImp> m_pStreamImp;
-  uint32_t m_dwAccess;
-};
-
 class CFGAS_TextStream : public IFGAS_Stream {
  public:
   template <typename T, typename... Args>
   friend CFX_RetainPtr<T> pdfium::MakeRetain(Args&&... args);
 
   // IFGAS_Stream
-  uint32_t GetAccessModes() const override;
   int32_t GetLength() const override;
   int32_t Seek(FX_STREAMSEEK eSeek, int32_t iOffset) override;
   int32_t GetPosition() override;
@@ -149,20 +113,20 @@ class CFGAS_TextStream : public IFGAS_Stream {
   int32_t WriteString(const wchar_t* pStr, int32_t iLength) override;
   void Flush() override;
   bool SetLength(int32_t iLength) override;
-  int32_t GetBOM(uint8_t bom[4]) const override;
+  int32_t GetBOMLength() const override;
   uint16_t GetCodePage() const override;
   uint16_t SetCodePage(uint16_t wCodePage) override;
 
  private:
-  explicit CFGAS_TextStream(const CFX_RetainPtr<IFGAS_Stream>& pStream);
+  CFGAS_TextStream(std::unique_ptr<IFGAS_StreamImp> imp, bool isWriteSteam);
   ~CFGAS_TextStream() override;
 
   void InitStream();
 
   uint16_t m_wCodePage;
   int32_t m_wBOMLength;
-  uint32_t m_dwBOM;
-  CFX_RetainPtr<IFGAS_Stream> m_pStreamImp;
+  bool m_IsWriteStream;
+  std::unique_ptr<IFGAS_StreamImp> m_pStreamImp;
 };
 
 class CFGAS_WideStringReadStream : public IFGAS_Stream {
@@ -171,7 +135,6 @@ class CFGAS_WideStringReadStream : public IFGAS_Stream {
   friend CFX_RetainPtr<T> pdfium::MakeRetain(Args&&... args);
 
   // IFGAS_Stream
-  uint32_t GetAccessModes() const override;
   int32_t GetLength() const override;
   int32_t Seek(FX_STREAMSEEK eSeek, int32_t iOffset) override;
   int32_t GetPosition() override;
@@ -182,7 +145,7 @@ class CFGAS_WideStringReadStream : public IFGAS_Stream {
   int32_t WriteString(const wchar_t* pStr, int32_t iLength) override;
   void Flush() override {}
   bool SetLength(int32_t iLength) override;
-  int32_t GetBOM(uint8_t bom[4]) const override;
+  int32_t GetBOMLength() const override;
   uint16_t GetCodePage() const override;
   uint16_t SetCodePage(uint16_t wCodePage) override;
 
@@ -194,7 +157,7 @@ class CFGAS_WideStringReadStream : public IFGAS_Stream {
   int32_t m_iPosition;
 };
 
-IFGAS_StreamImp::IFGAS_StreamImp() : m_dwAccess(0) {}
+IFGAS_StreamImp::IFGAS_StreamImp() {}
 
 CFGAS_FileReadStreamImp::CFGAS_FileReadStreamImp()
     : m_pFileRead(nullptr), m_iPosition(0), m_iLength(0) {}
@@ -269,8 +232,7 @@ CFGAS_FileWriteStreamImp::CFGAS_FileWriteStreamImp()
     : m_pFileWrite(nullptr), m_iPosition(0) {}
 
 bool CFGAS_FileWriteStreamImp::LoadFileWrite(
-    const CFX_RetainPtr<IFX_SeekableWriteStream>& pFileWrite,
-    uint32_t dwAccess) {
+    const CFX_RetainPtr<IFX_SeekableWriteStream>& pFileWrite) {
   ASSERT(!m_pFileWrite && pFileWrite);
 
   m_iPosition = pFileWrite->GetSize();
@@ -327,65 +289,58 @@ void CFGAS_FileWriteStreamImp::Flush() {
   }
 }
 
-CFGAS_TextStream::CFGAS_TextStream(const CFX_RetainPtr<IFGAS_Stream>& pStream)
+CFGAS_TextStream::CFGAS_TextStream(std::unique_ptr<IFGAS_StreamImp> imp,
+                                   bool isWriteStream)
     : m_wCodePage(FX_CODEPAGE_DefANSI),
       m_wBOMLength(0),
-      m_dwBOM(0),
-      m_pStreamImp(pStream) {
+      m_IsWriteStream(isWriteStream),
+      m_pStreamImp(std::move(imp)) {
   ASSERT(m_pStreamImp);
   InitStream();
 }
 
 CFGAS_TextStream::~CFGAS_TextStream() {}
 
+#if _FX_ENDIAN_ == _FX_LITTLE_ENDIAN_
+#define BOM_MASK 0x00FFFFFF
+#define BOM_UTF8 0x00BFBBEF
+#define BOM_UTF16_MASK 0x0000FFFF
+#define BOM_UTF16_BE 0x0000FFFE
+#define BOM_UTF16_LE 0x0000FEFF
+#else
+#define BOM_MASK 0xFFFFFF00
+#define BOM_UTF8 0xEFBBBF00
+#define BOM_UTF16_MASK 0xFFFF0000
+#define BOM_UTF16_BE 0xFEFF0000
+#define BOM_UTF16_LE 0xFFFE0000
+#endif  // _FX_ENDIAN_ == _FX_LITTLE_ENDIAN_
+
 void CFGAS_TextStream::InitStream() {
   int32_t iPosition = m_pStreamImp->GetPosition();
   m_pStreamImp->Seek(FX_STREAMSEEK_Begin, 0);
-  m_pStreamImp->ReadData((uint8_t*)&m_dwBOM, 3);
-#if _FX_ENDIAN_ == _FX_LITTLE_ENDIAN_
-  m_dwBOM &= 0x00FFFFFF;
-  if (m_dwBOM == 0x00BFBBEF) {
-    m_wBOMLength = 3;
-    m_wCodePage = FX_CODEPAGE_UTF8;
-  } else {
-    m_dwBOM &= 0x0000FFFF;
-    if (m_dwBOM == 0x0000FFFE) {
-      m_wBOMLength = 2;
-      m_wCodePage = FX_CODEPAGE_UTF16BE;
-    } else if (m_dwBOM == 0x0000FEFF) {
-      m_wBOMLength = 2;
-      m_wCodePage = FX_CODEPAGE_UTF16LE;
-    } else {
-      m_wBOMLength = 0;
-      m_dwBOM = 0;
-      m_wCodePage = FXSYS_GetACP();
-    }
-  }
-#else
-  m_dwBOM &= 0xFFFFFF00;
-  if (m_dwBOM == 0xEFBBBF00) {
+
+  uint32_t bom;
+  m_pStreamImp->ReadData(reinterpret_cast<uint8_t*>(&bom), 3);
+
+  bom &= BOM_MASK;
+  if (bom == BOM_UTF8) {
     m_wBOMLength = 3;
     m_wCodePage = FX_CODEPAGE_UTF8;
   } else {
-    m_dwBOM &= 0xFFFF0000;
-    if (m_dwBOM == 0xFEFF0000) {
+    bom &= BOM_UTF16_MASK;
+    if (bom == BOM_UTF16_BE) {
       m_wBOMLength = 2;
       m_wCodePage = FX_CODEPAGE_UTF16BE;
-    } else if (m_dwBOM == 0xFFFE0000) {
+    } else if (bom == BOM_UTF16_LE) {
       m_wBOMLength = 2;
       m_wCodePage = FX_CODEPAGE_UTF16LE;
     } else {
       m_wBOMLength = 0;
-      m_dwBOM = 0;
       m_wCodePage = FXSYS_GetACP();
     }
   }
-#endif
-  m_pStreamImp->Seek(FX_STREAMSEEK_Begin, std::max(m_wBOMLength, iPosition));
-}
 
-uint32_t CFGAS_TextStream::GetAccessModes() const {
-  return m_pStreamImp->GetAccessModes();
+  m_pStreamImp->Seek(FX_STREAMSEEK_Begin, std::max(m_wBOMLength, iPosition));
 }
 
 int32_t CFGAS_TextStream::GetLength() const {
@@ -405,34 +360,50 @@ bool CFGAS_TextStream::IsEOF() const {
 }
 
 int32_t CFGAS_TextStream::ReadData(uint8_t* pBuffer, int32_t iBufferSize) {
-  return m_pStreamImp->ReadData(pBuffer, iBufferSize);
+  ASSERT(pBuffer && iBufferSize > 0);
+
+  if (m_IsWriteStream)
+    return -1;
+
+  int32_t iLen = std::min(
+      m_pStreamImp->GetLength() - m_pStreamImp->GetPosition(), iBufferSize);
+  if (iLen <= 0)
+    return 0;
+
+  return m_pStreamImp->ReadData(pBuffer, iLen);
 }
 
 int32_t CFGAS_TextStream::WriteData(const uint8_t* pBuffer,
                                     int32_t iBufferSize) {
+  ASSERT(pBuffer && iBufferSize > 0);
+
+  if (!m_IsWriteStream)
+    return -1;
   return m_pStreamImp->WriteData(pBuffer, iBufferSize);
 }
 
 void CFGAS_TextStream::Flush() {
+  if (!m_IsWriteStream)
+    return;
   m_pStreamImp->Flush();
 }
 
 bool CFGAS_TextStream::SetLength(int32_t iLength) {
+  if (!m_IsWriteStream)
+    return false;
   return m_pStreamImp->SetLength(iLength);
 }
 
-uint16_t CFGAS_TextStream::GetCodePage() const {
-  return m_wCodePage;
-}
-
-int32_t CFGAS_TextStream::GetBOM(uint8_t bom[4]) const {
+int32_t CFGAS_TextStream::GetBOMLength() const {
   if (m_wBOMLength < 1)
     return 0;
-
-  *(uint32_t*)bom = m_dwBOM;
   return m_wBOMLength;
 }
 
+uint16_t CFGAS_TextStream::GetCodePage() const {
+  return m_wCodePage;
+}
+
 uint16_t CFGAS_TextStream::SetCodePage(uint16_t wCodePage) {
   if (m_wBOMLength > 0)
     return m_wCodePage;
@@ -446,7 +417,7 @@ int32_t CFGAS_TextStream::ReadString(wchar_t* pStr,
                                      int32_t iMaxLength,
                                      bool& bEOS) {
   ASSERT(pStr && iMaxLength > 0);
-  if (!m_pStreamImp)
+  if (m_IsWriteStream)
     return -1;
 
   if (m_wCodePage == FX_CODEPAGE_UTF16LE ||
@@ -489,7 +460,7 @@ int32_t CFGAS_TextStream::ReadString(wchar_t* pStr,
 
 int32_t CFGAS_TextStream::WriteString(const wchar_t* pStr, int32_t iLength) {
   ASSERT(pStr && iLength > 0);
-  if ((m_pStreamImp->GetAccessModes() & FX_STREAMACCESS_Write) == 0)
+  if (!m_IsWriteStream)
     return -1;
 
   if (m_wCodePage == FX_CODEPAGE_UTF8) {
@@ -505,129 +476,12 @@ int32_t CFGAS_TextStream::WriteString(const wchar_t* pStr, int32_t iLength) {
   return iLength;
 }
 
-CFGAS_Stream::CFGAS_Stream(std::unique_ptr<IFGAS_StreamImp> imp,
-                           uint32_t dwAccess)
-    : m_pStreamImp(std::move(imp)), m_dwAccess(dwAccess) {}
-
-CFGAS_Stream::~CFGAS_Stream() {}
-
-uint32_t CFGAS_Stream::GetAccessModes() const {
-  return m_dwAccess;
-}
-
-int32_t CFGAS_Stream::GetLength() const {
-  return m_pStreamImp ? m_pStreamImp->GetLength() : -1;
-}
-
-int32_t CFGAS_Stream::Seek(FX_STREAMSEEK eSeek, int32_t iOffset) {
-  if (!m_pStreamImp)
-    return -1;
-  return m_pStreamImp->Seek(eSeek, iOffset);
-}
-
-int32_t CFGAS_Stream::GetPosition() {
-  if (!m_pStreamImp)
-    return -1;
-  return m_pStreamImp->GetPosition();
-}
-
-bool CFGAS_Stream::IsEOF() const {
-  return m_pStreamImp ? m_pStreamImp->IsEOF() : true;
-}
-
-int32_t CFGAS_Stream::ReadData(uint8_t* pBuffer, int32_t iBufferSize) {
-  ASSERT(pBuffer && iBufferSize > 0);
-  if (!m_pStreamImp)
-    return -1;
-
-  int32_t iLen = std::min(
-      m_pStreamImp->GetLength() - m_pStreamImp->GetPosition(), iBufferSize);
-  if (iLen <= 0)
-    return 0;
-
-  return m_pStreamImp->ReadData(pBuffer, iLen);
-}
-
-int32_t CFGAS_Stream::ReadString(wchar_t* pStr,
-                                 int32_t iMaxLength,
-                                 bool& bEOS) {
-  ASSERT(pStr && iMaxLength > 0);
-  if (!m_pStreamImp)
-    return -1;
-
-  int32_t iLen =
-      std::min((m_pStreamImp->GetLength() - m_pStreamImp->GetPosition()) / 2,
-               iMaxLength);
-  if (iLen <= 0)
-    return 0;
-  return m_pStreamImp->ReadString(pStr, iLen, bEOS);
-}
-
-int32_t CFGAS_Stream::WriteData(const uint8_t* pBuffer, int32_t iBufferSize) {
-  ASSERT(pBuffer && iBufferSize > 0);
-  if (!m_pStreamImp)
-    return -1;
-  if ((m_dwAccess & FX_STREAMACCESS_Write) == 0)
-    return -1;
-  return m_pStreamImp->WriteData(pBuffer, iBufferSize);
-}
-
-int32_t CFGAS_Stream::WriteString(const wchar_t* pStr, int32_t iLength) {
-  ASSERT(pStr && iLength > 0);
-  if (!m_pStreamImp)
-    return -1;
-  if ((m_dwAccess & FX_STREAMACCESS_Write) == 0)
-    return -1;
-  return m_pStreamImp->WriteString(pStr, iLength);
-}
-
-void CFGAS_Stream::Flush() {
-  if (!m_pStreamImp)
-    return;
-  if ((m_dwAccess & FX_STREAMACCESS_Write) == 0)
-    return;
-  m_pStreamImp->Flush();
-}
-
-bool CFGAS_Stream::SetLength(int32_t iLength) {
-  if (!m_pStreamImp)
-    return false;
-  if ((m_dwAccess & FX_STREAMACCESS_Write) == 0)
-    return false;
-  return m_pStreamImp->SetLength(iLength);
-}
-
-int32_t CFGAS_Stream::GetBOM(uint8_t bom[4]) const {
-  if (!m_pStreamImp)
-    return -1;
-  return 0;
-}
-
-uint16_t CFGAS_Stream::GetCodePage() const {
-#if _FX_ENDIAN_ == _FX_LITTLE_ENDIAN_
-  return FX_CODEPAGE_UTF16LE;
-#else
-  return FX_CODEPAGE_UTF16BE;
-#endif
-}
-uint16_t CFGAS_Stream::SetCodePage(uint16_t wCodePage) {
-#if _FX_ENDIAN_ == _FX_LITTLE_ENDIAN_
-  return FX_CODEPAGE_UTF16LE;
-#else
-  return FX_CODEPAGE_UTF16BE;
-#endif
-}
-
 CFGAS_WideStringReadStream::CFGAS_WideStringReadStream(
     const CFX_WideString& wsBuffer)
     : m_wsBuffer(wsBuffer), m_iPosition(0) {}
 
 CFGAS_WideStringReadStream::~CFGAS_WideStringReadStream() {}
 
-uint32_t CFGAS_WideStringReadStream::GetAccessModes() const {
-  return 0;
-}
-
 int32_t CFGAS_WideStringReadStream::GetLength() const {
   return m_wsBuffer.GetLength() * sizeof(wchar_t);
 }
@@ -688,7 +542,7 @@ bool CFGAS_WideStringReadStream::SetLength(int32_t iLength) {
   return false;
 }
 
-int32_t CFGAS_WideStringReadStream::GetBOM(uint8_t bom[4]) const {
+int32_t CFGAS_WideStringReadStream::GetBOMLength() const {
   return 0;
 }
 
@@ -714,8 +568,7 @@ CFX_RetainPtr<IFGAS_Stream> IFGAS_Stream::CreateReadStream(
            ->LoadFileRead(pFileRead)) {
     return nullptr;
   }
-  return pdfium::MakeRetain<CFGAS_TextStream>(
-      pdfium::MakeRetain<CFGAS_Stream>(std::move(pImp), 0));
+  return pdfium::MakeRetain<CFGAS_TextStream>(std::move(pImp), false);
 }
 
 // static
@@ -727,12 +580,10 @@ CFX_RetainPtr<IFGAS_Stream> IFGAS_Stream::CreateWriteStream(
   std::unique_ptr<IFGAS_StreamImp> pImp =
       pdfium::MakeUnique<CFGAS_FileWriteStreamImp>();
   if (!static_cast<CFGAS_FileWriteStreamImp*>(pImp.get())
-           ->LoadFileWrite(pFileWrite, FX_STREAMACCESS_Write)) {
+           ->LoadFileWrite(pFileWrite)) {
     return nullptr;
   }
-
-  return pdfium::MakeRetain<CFGAS_TextStream>(
-      pdfium::MakeRetain<CFGAS_Stream>(std::move(pImp), FX_STREAMACCESS_Write));
+  return pdfium::MakeRetain<CFGAS_TextStream>(std::move(pImp), true);
 }
 
 // static
diff --git a/xfa/fgas/crt/ifgas_stream.h b/xfa/fgas/crt/ifgas_stream.h
index df9d93afa3..b3f8a928d8 100644
--- a/xfa/fgas/crt/ifgas_stream.h
+++ b/xfa/fgas/crt/ifgas_stream.h
@@ -11,10 +11,6 @@
 #include "core/fxcrt/fx_stream.h"
 #include "core/fxcrt/fx_system.h"
 
-enum FX_STREAMACCESS {
-  FX_STREAMACCESS_Write = 0x04,
-};
-
 enum FX_STREAMSEEK {
   FX_STREAMSEEK_Begin = 0,
   FX_STREAMSEEK_Current,
@@ -30,7 +26,6 @@ class IFGAS_Stream : public CFX_Retainable {
   static CFX_RetainPtr<IFGAS_Stream> CreateWideStringReadStream(
       const CFX_WideString& buffer);
 
-  virtual uint32_t GetAccessModes() const = 0;
   virtual int32_t GetLength() const = 0;
   virtual int32_t Seek(FX_STREAMSEEK eSeek, int32_t iOffset) = 0;
   virtual int32_t GetPosition() = 0;
@@ -41,7 +36,7 @@ class IFGAS_Stream : public CFX_Retainable {
   virtual int32_t WriteString(const wchar_t* pStr, int32_t iLength) = 0;
   virtual void Flush() = 0;
   virtual bool SetLength(int32_t iLength) = 0;
-  virtual int32_t GetBOM(uint8_t bom[4]) const = 0;
+  virtual int32_t GetBOMLength() const = 0;
   virtual uint16_t GetCodePage() const = 0;
   virtual uint16_t SetCodePage(uint16_t wCodePage) = 0;
 };